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The sun's magnetic north and south poles have flipped positions, ushering in a period of peak solar activity that could trigger problems on Earth. Astronomers announced this week that the bipolar switch, referred to as Solar Max or solar maximum, had not been a surprise. The magnetic flip between the sun's northern and southern hemispheres occurs once every 11 years.
During the Solar Max, solar blasts traveling toward the earth can trigger dramatic aurora displays at night while also wreaking havoc on power grids and communications satellites. The sun typically exhibits more sunspots and throws out an increased number of solar flares, sending powerful blasts of charged particles into the solar system. NASA physicist David Hathaway said, "This always happens around the time of solar maximum. The magnetic poles exchange takes places at the peak of the sunspot cycle. In fact, it's a good indication that Solar Max is really here."
Although the Earth can also reverse its magnetic fields, scientists estimate that the last flip occurred 740,000 years ago
Source : Nature
